Nonresonant supporting device



Aug. 20, 1935. A. w. HULL 2,012,129

NONRESONANT SUPPORTING DEVICE Filed Dec. 15, 1928 Inventor: Albert. W. Hull,

His Attorney.

Patented Aug. 20, 1935 PAT sNrjoFFrc v '2;012 29* V a. 1 NONRESONAN'IIgSUPPORTINQ 7 Albert Hull, 'Schenectaily, N.. Y., 'assignorjto a General Electric Company, a. corporation-of 3 New York a ion December 15, 1928, SerialNo.'326 ,169

V fleeiai' s. ('o1.2'50;-'2 7.5 r The present invention relatesbroadly to d vices for supporting objects subject to vibration and fordraining, off the vibratory :energy; The invention has particular application to thermi- ,5 onic apparatus whereinfthe vibratory movement of the electrodes; gives rise to microphonic noises in the output circuit.

InWhree-electrode apparatus which usually comprises a filament, grid and anode, the heated memberv is suspended'in a manner such as to allow for expansion under operating conditions. The filament support may take the fQIm-Of a coiled spring in thelarger apparatus but in the I small receiver types of tubes, it has been found sufiicient from a practicalstandpointtoprovide rigid supports; however,'in the case of the small tubes the filament, whenljleatedselongates and may tend to vibrate or sway slightly toward the changes in position of the filament relative to the.

adjacent electrode, it is also to be understood that when the remaining electrodes, 1. e,, the grid and anode; are made of relatively 'flightimaterial 3 tor in case there is undue flexibility of their supporting means, these electrodes mayalso add their vibrational effectto that of thefilame'nt, resulting in still greater noise; howeven; the or-.

, der of magnitude of the filament vibrational en- 3 ergy is usually much greater than that' f'the othergelectrodes considered either separately or asaunit',

I have discovered and'inra'ccord'ance with my invention that by. providing (a special form of 4 support'fonthe' electrode structure not only is the .vibrational energy o f thefilament efiectively dampedabut'alsow such energy of this character as may be contributed by the various other' elec ltrodes'.

provide a substantially aperiodic support for members subject to vibration, which will'effec- .tively drain the vibrational energy fromsaid members, moreparticularly from the filament several views.

"Among the objects of my invention areto and other electrodes ,of.a thermionic device; to

. relative: positions of the various-electrodes or swing-slightly the entire electrical structure about features will be apparent as thespecification is perused in' connection with the accompanying drawing in which similar reference characters designate corresponding elements throughout the Fig. 1 is an elevational view in perspective of a thermionic discharge'device. equipped with the improved electrode support Fig. 2; illustrates a modified form. of electrode unit and supporting member, while Fig.3 shows'theimprovedsup- 10 porting cable in;the process or making.

Referring tc Fig.1, I have indicated at I an evacuated envelop containing a filamentary oath: ode 2,a'helical grid'3, and an anode 4, the two latter members surrounding the filarnent in con- .15 I

centric fashion. The anode is formed preferably of a curved plate member with terminal'fianges i between which'is clamped anuprightsup'port rod 5 secured in the press at the lower end and extended to serve as a leading-in conductor. The 9 upper end of the rod carries a horizontally dis-t posed member, one end of which is affixed in a block 6 of insulating material. The block is also supported by a wire attached to upright l'which" is spot-welded to the convolutions of'the grid 5 and which extends through the press'to form another lead ing-in conductor. The position of the lower end of the'filament is maintained by a' stiff wire, theupperj end being suspended from an aperiodic supporting member 8 described herematter which may also serve as a lead, This 7 member takes theform of a. stranded cable or red comprising a plurality of parallel wires 9, specifically shown as six and preferably constituted of ametaL-such'a's iron or copper, bound 5 tightly togetherbya Wire l9 preferably of the same material, as seen moreclearly in Fig.3.

The lengthof cable may be finished off by securing'together, by welding for example, the last tilever effect for clearing the electrode structure. :The lower: end of the member 8 is affixed in posi-' tion by a sheet metalclamp l I which fits tightly 7 over the press and pinches the upstanding support. In order'to assure no'turning movement between the aperiodic member and the clamp, a

"rigid I ire I2 is provided, extending from the bend in therod to the block 6. 0

{It will be evident that when there is setup within or without the envelop inecham'cal -dis-,

turbances whichjnormally would displace the the lower rigid wires as a fulcrum, pendulum fashion, resulting in undulationsoi audible character, the vibrational energy transmitted to the active member will be effectively dissipated in the aperiodic support 8.

While I do not wish to be limited to any particularly theory, it seems that when the rod 8 is subjected to stress with resulting strain as would be the case under the conditions noted, the wires 8 rub against one another and expend the superfiuous energy as friction and generated heat, without passing the undulatory motion to the electrodes. The completeness and rapidity with which waves are damped and dissipated depend upon the design of the non-microphonic member.

Among the factors which determine these characteristics are the spacing between adjacent turns and the number, size and nature of the wires em ployed. It has been found that the spacing of the convolutions has somewhat the same'efiect on localized disturbances, such as a tap on the en.

velop or other glass portions from being communicated to the electrode structure. In short the rod 8 .may be considered mechanically to isolate the electrodesfrom jar arising within or without the envelop.

Fig 2 shows anelectrode organization suspended entirely between lengths of the improved support. This modification is similar to that described with respect to Fig. 1 except there are provided a short length of cable l3 attachedto the overhanging portion of themain stem 8 and another short length M, which supports the lower insulation block I5. These short pieces preferably are of smaller diameter than the main upright 8 and may be constructed of a fewer number of wires or perhaps of the same number of wires of smaller gage. The block iii-carries the lower end of the electrodes by means of suitable connections. The lead wires l6 and ii for the grid and anode respectively, are constituted of relatively small wires so as to minimize I the amount of material of the microphonic sort necessary, also to provide maximumfiexibility so.as not to disturb or curtail the damping function of the aperiodic supports. The filament may be energized by current passing through the cables Band l4.

The electrode structure is preferably positioned in the envelop (not shown) by means ofmetallic band 18 clamped about thestem to form a holder for the upright member 8. When the cable is longand slender, it may be necessary toprovide a transverse support l9 intermediate the ends of the vertical portion, one end of which is affixed in the press and the other end. having a hook-like extremity which. grasps the. upright in the manner shown. It is apparent that the entire electrode structure is supported, top and bottom, by an aperiodic member forming a-structure which completely isolates the electrodes, particularly the filament, from vibrations that impinge on the glass envelop. These members operate precisely in the same manneras was. ex-

plained with respect to :the preceding figure.

vibratory disturbances are to be dissipated particularly-where the energy to be drained is of relatively large amplitude. As examples tending to show the extended use of a cable such as described there may be mentioned its employment as an airplane strut, wire rope or cord by which objects in general are suspended or supported the airplane and objects being susceptible to vibration of an-excessive character.

What I claim as new. and desire to secure by Letters Patent oi the United States, is:

l. A' thermionic device comprising an envelop containing a plurality of cooperative electrodes and means within the envelop for supporting the electrodes, said means comprising a substantially non-microphonic metallic member, said mem ber being constituted of superimposed wires.

2. A thermionic'device comprising an envelop containing a plurality ofcooperative electrodes andmeans for supporting the electrodes within the "envelop, said means comprising a multistrand cable designed to be substantially nonmicrophonic at all frequencies. I a

3. A non-microphonic electrode supportcomprising a plurality of parallel metallic wires bound together by a helical member.

4. A thermionic device comprising. an envelop containing a plurality of cooperative electrodes, including a filament and means fordraining vibrational energy from said filament, said means comprising a plurality of wires in contact with one another and having a relative movement therebetween.

5. Electrode structure for a thermionic device comprising an electrode supported at. each end within the device .by a substantially aperiodic member, said member consisting of a plurality of wires arranged'to allow a rucbing contact be tween one another, i I I 6. An electrode structurejfor electric discharge devices, said structure including faplurality of electrodes rigidly secured together in spaced relation, and meansfor supporting the structure as a whole within the device, saidmeans comprising a pair of substantially non-.microphonic members secured respectively to opposite. ends of thestructure, each member consisting ofa plurality of wires which contact with one another alongtheir respective lengths and are bound together.

7. A thermionic. devicecomprising an envelop containing an electrode organization, blocks of insulating material positioned at each end of the electrode organization, rigid members connectingsaid blocks to the electrodes, and means for supporting saidblocks within the envelop, said means being substantially aperiodic to all frequencies and comprising a plurality of wires which'contact with one another and have a relative movement therebetween.

8. A thermionic device comprising an envelop terminating in a reentrant stem andcontaining an electrode, organization, blocks of insulating material positioned atfeach endof the electrode dampening member'of smaller dimension which organization and arranged" at different distances from said stem, rigid members connecting said blocks to the electrodes, supports between each of saidblocks and the reentrantstem, the support for the block positioned remote from the mension being connected to the remotelypositioned block, the support for the block nearer the'stem being constituted of a vibration-dampening member having a cross-sectional dimen sion substantially the same as the vibrationis secured to the other of said blocks. q

; '9. A thermionic device comprising an envelop containinga' plurality of cooperative electrodes, including a filament,'and means comprising a substantially non-microphonic conductor for vcarrying current to said filament and for preventing vibrations of substantially all frequencies from being-communicated to'said filament, said 7 conductor being constituted of superimposed 10 metallicwires, f s v a ALBERT W. HULL. 

